Collective measurements on identically prepared quantum systems can extract more information than local measurements, thereby enhancing information-processing efficiency. Although this nonclassical phenomenon has been known for two decades, it remained a challenging task to demonstrate the advantage of collective in experiments. Here, we introduce general recipe performing deterministic qubits based walks. Using photonic walks, realize experimentally an optimized measurement with fidelity...

Quantum metrology overcomes standard precision limits and plays a central role in science technology. Practically, it is vulnerable to imperfections such as decoherence. Here we demonstrate quantum for noisy channels that entanglement with ancillary qubits enhances the Fisher information phase estimation but not otherwise. Our photonic experiment covers range of noise various types channels, including two randomly alternating assisted fails each channel individually. We simulate by...

Amblyopia is a common cause of visual impairment in children. Compliance with traditional treatments for amblyopia challenging due to negative psychosocial impacts. Recent shifts treatment have moved from suppressing the dominant eye enhancing binocular function. Binocular digital therapy has become promising approach. The aim this study was evaluate effects gamified on acuity and stereoacuity (SA) children unilateral amblyopia. This pilot prospective enrolled 11 aged 4-6 years Following at...

Quantum memory, serving as a crucial device for storing and releasing quantum states, holds significant importance in long-distance communications. Up to date, memories have been realized many different systems. However, most of them complex structures high costs. Besides, it is not easy simultaneously achieve both storage efficiency fidelity. In this paper, we experimentally demonstrate low-cost optical memory with fidelity, by utilizing butterfly shaped cavity consisting one polarization...

Reference-frame-independent (RFI) measurement-device-independent (MDI) quantum key distribution (QKD) is immune to all detector side-channel attacks and insensitive slow drifts of reference frames; thus, it a promising candidate for the realization long-distance secure communications. However, its practical performance predominantly limited by finite-data-size effect compared with standard MDI QKD. By combining collective constraint joint-study strategy our parameter estimation processes...

Some aspects of human metacognition, such as the ability to consciously evaluate our beliefs and decisions, are hypothesized be culturally acquired. However, direct evidence for this claim is lacking. As an initial step toward answering question, here we examine differences in metacognitive performance between populations matched occupation (students), income, demographics general intelligence but drawn from 2 distinct cultural milieus (Beijing, China London, U.K.). Chinese participants...

Most gold ores have variable sulfur isotopic and trace elemental compositions at micro-/nano-scale, which makes the understanding of formation process more challenging. The advancement in-situ analytical techniques offer opportunity to gain insight into mineralization processes ore-material source. Xiaotongjiapuzi is a representative intrusion-related deposit in Qingchengzi orefield Liaodong Peninsula, Eastern China. Alteration comprise four stages: (I) quartz-pyrite-Au, (II)...

Measurement-device-independent quantum key distribution (MDI QKD) is a promising method for remote sharing that can eliminate all detector side-channel attacks. However, current security proofs often overlook the potential information leakages from legitimate users' devices. In version of Trojan-horse attack (THA), malicious eavesdropper inject bright light into sources MDI QKD system and then analyze back-reflected to obtain their setting choices, thereby compromising final security. Here,...

Among all present quantum key distribution protocols, the reference-frame-independent measurement-device-independent (RFI-MDI-QKD) is standing out due to its high security and practicability, since it can not only remove detector-side-channel attacks, but also relax requirement of reference-frame calibrations. However, till today, performance degradation RFI-MDI-QKD caused by finite-size effects one biggest impediment practical implementations. Here, we propose an enhanced protocol which...

The measurement-device-independent quantum key distribution (MDI-QKD) can be immune to all detector side-channel attacks. Moreover, it easily implemented combining with the matured decoy-state methods under current technology. It thus seems a very promising candidate in practical implementation of communications. However, suffers from severe finite-data-size effect most existing MDI-QKD protocols, resulting relatively low rates. Recently, Jiang et al. [Phys. Rev. A 103, 012402 (2021)]...

Quantum steering is one form of quantum correlations interpolating between entanglement and Bell nonlocality, which in some cases can be detected by various inequalities. Recently, a remarkable useful steerability criterion via geometric Bell-like inequalities was established [M. Zukowski, A. Dutta, Z. Yin, Phys. Rev. A 91, 032107 (2015)]. We report an experimental investigation this verify the inequality experimentally using Werner states. The results demonstrate that convenient tool to...

We propose a simple and reliable method for engineering tunable Werner state realize it experimentally. The whole setup mainly includes parametric down-conversion source controllable depolarization channel which consists of Sagnac-like interferometer some complete dephasing operations. generated states are characterized by quantum tomography, very high concurrences fidelities can be achieved.

Einstein-Podolsky-Rosen steering is an intermediate relationship between entanglement and Bell nonlocality in the hierarchical structure of quantum nonlocality. To certify steerability entangled state, Mermin inequality supposed to be violated by exceeding bound 2. We present experimental generation post-selected three-photon states witness a maximal violation up 3.50±0.05. In context observing which requires measuring on GHZ we derive tight lower GHZ-fidelity that can certified from...

In this paper, we carry out investigation on the HOM interference between two independent photons by using filters with different bandwidth both in theory and experiment. Our experimental results are consistent theoretical predictions. From results, find that a narrower can help to give larger coherence length, due broadening of photon wave-packet spatial domain, resulting an higher visibility. Furthermore, combination bandwidths may achieve nice balance coincidence counting rate present...

The measurement-device-independent quantum key distribution (MDI QKD) can resist all attacks against measurement devices. However, its practical performance is still limited due to very low coincidence counting rates in Bell-state measurements. In this paper, we propose a memory-assisted MDI QKD protocol by cooperating the heralded single-photon sources and an all-optical memory. By making use of heralding characteristic sources, earlier photon will be stored Sagnac optical memory, then...

LLM-based Automatic Prompt Optimization, which typically utilizes LLMs as Optimizers to self-reflect and refine prompts, has shown promising performance in recent studies. Despite the success, underlying mechanism of this approach remains unexplored, true effectiveness requires further validation. In work, we conducted a comprehensive study uncover actual Optimization. Our findings reveal that LLM optimizers struggle identify causes errors during reflection, tending be biased by their own...

Abstract Quantum digital signature (QDS) can guarantee the information-theoretical security of a with fundamental laws quantum physics. However, most current QDS protocols do not take source into account, leading to an overestimation rate. In this paper, we propose utilize Hong-Ou-Mandel interference characterize upper-bound imperfections, and further quantify information leakage from potential side-channels. Additionally, combine decoy-state methods finite-size analysis in analyzing...

Measurement-device-independent quantum key distribution (MDI-QKD) can remove all detection side channels but still makes additional assumptions on sources that be compromised through uncharacterized in practice. Here, we combine a recently proposed reference technique to prove the security of MDI-QKD against possible source imperfections and/or channels. This requires some states and an upper bound parameter describes quality sources. With this formalism investigate asymptotic performance...

Measurement-device-independent quantum key distribution (MDI-QKD) removes all detector side-channel attacks and guarantees a promising way for remote secret keys sharing. Several proof-of-principal experiments have been demonstrated to show its security practicality. However, these practical implementations demand mostly, example, perfect state preparation or completely characterized sources ensure security, which are difficult realize with prior art. Here, we investigate three-state MDI-QKD...